1. Field of the Invention
The present invention relates to a power tool and more particularly, to a technique for effectively utilizing cooling air of a drive motor within a power tool.
2. Description of the Related Art
Japanese non-examined and laid-open patent publication No. 8-336803 discloses a technique of cooling the drive motor for driving a tool bit within a power tool. According to this technique, cooling air is introduced into a motor housing by rotating a fan blade so as to cool the drive motor. Then, the cooling air is led into the blade case through a partition structure that defines a cooling air passage between the motor housing and the blade case. According to this technique, the partition structure is designed and configured to improve the motor cooling efficiency.
Above-described prior art relates to a technique for improving the motor cooling efficiency or the fan performance utilizing a fan blade. On the other hand, further improvement is desired to rationalize the entire structure of a power tool.